The herald patch

The next stage is usually the appearance of a pink or red oval patch of scaly skin that grows larger over the course of a few days. This is known as the "herald patch". It ranges in size from 2cm to 10cm (0.8-4 inches).

The patch usually appears on your tummy, chest, back or neck. Occasionally, the patch can appear on your face or scalp, or near your genitals.

Rash

A skin rash will usually develop within a few days to two weeks after the appearance of the herald patch, and it may continue to spread over the following two to six weeks.

The rash is made up of smaller raised scaly patches that usually range in size from 0.5cm to 1.5cm. Most people will develop many patches across their chest, back, tummy, neck, upper arms and upper thighs. The face is usually unaffected.

In light-skinned people, the patches are usually a pinkish-reddish colour. In dark-skinned people, the patches can sometimes be grey, dark brown or black.

The patches usually form a "Christmas tree pattern" on the upper back and a v-shape across the chest.

The rash isn't painful, but it can be itchy. The itchiness can range from mild to severe. It's often made worse by sweating and wearing tight-fitting clothing.

In most cases, both the herald patch and skin rash will clear within 12 weeks, although occasionally it persists for up to five months.

After the rash has disappeared, you may notice some darkened or lightened areas of skin. These should return to normal within a few months. Pityriasis rosea doesn't cause scarring.